JP5546316B2 - Succinimide compound, lubricating oil additive and lubricating oil composition - Google Patents

Description

  The present invention relates to a novel succinimide compound, and a lubricating oil additive and lubricating oil composition containing the compound.

  A succinimide compound is used as an ashless dispersant that disperses an insoluble matter to be generated in oil in the field of lubricating oil for internal combustion engines such as gasoline engine oil and diesel engine oil. On the other hand, succinimide compounds are used as friction modifiers for increasing frictional force in the field of drive system lubricants such as automatic transmissions.

  As a conventional succinimide compound, a succinimide compound obtained by reaction of a succinic anhydride substituted with a high molecular weight alkenyl or alkyl group and a polyalkylene polyamine is known (Patent Document 1 below). See ~ 3.)

JP-A-2005-146148 Japanese Patent Laid-Open No. 10-265793 JP-A-10-219269

  The present invention relates to a novel succinimide compound useful for applications such as an ashless dispersant in a lubricating oil for internal combustion engines, a friction modifier in a drive system lubricating oil, and a lubricating oil additive and a lubricating oil composition containing the compound. The purpose is to provide.

［式（１）中、Ｒは数平均分子量５００以上５０００未満のアルキル基又はアルケニル基を示す。］ Therefore, the present invention provides a succinimide compound represented by the following formula (1).

[In the formula (1), R represents an alkyl group or alkenyl group having a number average molecular weight of 500 or more and less than 5000. ]

  Since the succinimide compound of the present invention has very superior characteristics compared to conventional succinimide compounds, it is suitable for use in ashless dispersants in internal combustion engine lubricants, friction modifiers in drive device lubricants, etc. Useful for applications.

  For example, recently, drive system lubricants are required to have a higher coefficient of friction than conventional ones in order to efficiently convert the friction force inside the automatic transmission into drive force from the viewpoint of improving fuel efficiency. However, when a conventional succinimide compound as described in Patent Documents 1 to 3 above is used, a sufficient effect of improving friction characteristics cannot be obtained. In addition, in the case of the conventional succinimide compound, the cause is that the succinimide compound itself has an insufficient effect of improving the friction characteristics, and if the amount of succinimide is increased, the adsorptivity to the metal surface is increased. May change, and the balance of other additives may be lost, resulting in deterioration of friction characteristics.

  On the other hand, the succinimide compound of the present invention is superior in the effect of improving the friction characteristics as compared with the conventional succinimide compound, so that the frictional force inside the automatic transmission is efficiently converted to the driving force. A high coefficient of friction can be achieved, and fuel efficiency can be improved.

  In the succinimide compound of the present invention, R in the formula (1) is preferably a group derived from polyisobutene having a number average molecular weight of 500 or more and less than 5000.

  The present invention also provides a lubricating oil additive containing the succinimide compound of the present invention.

  The present invention also provides a lubricating oil composition comprising a lubricating base oil and the succinimide compound of the present invention.

  The lubricating oil composition of the present invention preferably further contains a phosphorus compound.

  According to the present invention, a novel succinimide compound useful for applications such as an ashless dispersant in an internal combustion engine lubricating oil, a friction modifier in a drive system lubricating oil, and a lubricating oil additive and lubricating oil containing the compound It becomes possible to provide a composition.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

［式（１）中、Ｒは数平均分子量５００以上５０００未満のアルキル基又はアルケニル基を示す。］ [Succinimide compounds]
The succinimide compound according to the present embodiment has a structure represented by the following formula (1).

[In the formula (1), R represents an alkyl group or alkenyl group having a number average molecular weight of 500 or more and less than 5000. ]

  In the formula (1), the alkyl group or alkenyl group represented by R is preferably a polybutenyl group or a polyisobutenyl group. The number average molecular weight of the alkyl group or alkenyl group represented by R is 500 or more and less than 5000, preferably 700 to 4000, more preferably 800 to 3500.

  The succinimide compound represented by the formula (1) is a maleated alkyl or maleated alkenyl having an alkyl group or alkenyl group having a number average molecular weight of 500 or more and less than 5000, and phenylalanine (2-amino-3-phenylpropionic acid). Can be obtained by reaction. The maleated alkyl or maleated alkenyl used as a raw material can be obtained, for example, by reacting a polyalkene (polybutene, polyisobutene, etc.) having a number average molecular weight of 500 or more and less than 5000 with maleic anhydride.

  When the maleated alkyl or maleated alkenyl is reacted with phenylalanine, the charged ratio of maleated alkyl or maleated alkenyl / phenylalanine is preferably a molar ratio, preferably 1/1 to 1/2, more preferably 1/1. To 1 / 1.8, more preferably 1 / 1.1-1 / 1.6, and particularly preferably 1 / 1.2-1 / 1.5. By carrying out the reaction at a ratio in the above range, the objective succinimide compound can be obtained more reliably.

In addition, in said reaction, the succinimide compound represented by following formula (2) other than the succinimide compound represented by Formula (1) can byproduce. In this case, the succinimide compound represented by the formula (2) may be separated and removed from the reaction product, and only the formula (1) succinimide compound may be used as a lubricating oil additive, or represented by the formula (1). A mixture of the succinimide compound and the succinimide compound represented by formula (2) may be used as a lubricating oil additive.

  In the formula (2), R represents an alkyl group or alkenyl group having a number average molecular weight of 500 or more and less than 5000. n represents an integer of 1 or more. Note that n is usually 1 or 2, but when the ratio of phenylalanine to maleated alkyl or maleated alkenyl in the raw material is large during synthesis, n tends to increase.

  Further, the succinimide compound represented by the formula (1) may be used as it is without being boronated (that is, as a non-boronated succinimide compound) or may be used as a boronated succinimide compound. . Further, a boronated succinimide compound and a non-borated succinimide compound may be used in combination.

  The boronated succinimide compound can be obtained by reacting a boron-containing compound with a succinimide compound represented by the formula (1) at a temperature of usually 50 to 250 ° C, preferably 100 to 200 ° C. it can. Examples of the boron-containing compound include boron oxide, boron halide, boric acid, boric anhydride and boric acid ester. These boron-containing compounds may be used alone or in combination of two or more.

[Lubricant additive]
The lubricating oil additive according to this embodiment contains a succinimide compound represented by the above formula (1). The lubricating oil additive may consist only of the succinimide compound represented by the formula (1), and may be a mixture of the succinimide compound represented by the formula (1) and other additives. There may be. The lubricating oil additive may further contain a diluent for dissolving the additive.

  In addition, since the succinimide compound represented by the formula (1) is excellent in compatibility with various additives used in the lubricating oil field, the lubricant additive according to the present embodiment is represented by the formula (1). In the case of a mixture of the succinimide compound and other additives, the other additives used in combination are not particularly limited. Therefore, the kind of other additive used together with the succinimide compound represented by the formula (1) and the blending amount of both can be appropriately selected according to the use and purpose of the lubricating oil additive. Specific examples of other additives used in combination will be described later.

  The lubricating oil composition according to this embodiment contains a lubricating base oil and a succinimide compound represented by the above formula (1). In addition, the aspect containing the lubricating base oil and the lubricating oil additive which concerns on the said embodiment is included in the said lubricating oil composition.

  The lubricating base oil is not particularly limited, and any of mineral oil and synthetic oil can be used. Various conventionally known oils can be used as the mineral oil, and examples thereof include paraffin-based mineral oil, intermediate-based mineral oil, and naphthene-based mineral oil. Specifically, light neutral oil, intermediate neutral oil, heavy neutral oil, bright stock, etc. by solvent refining or hydrogen refining can be mentioned. Alternatively, GTL base oil obtained by isomerizing wax may be used, and the effect increases as the degree of purification increases.

  As the synthetic oil, various conventionally known oils can be used. For example, poly α-olefin (including α-olefin copolymer), polybutene, polyol ester, dibasic acid ester, phosphate ester, polyphenyl ether, alkylbenzene, alkylnaphthalene, polyoxyalkylene glycol, neopentyl glycol, silicone Oil, trimethylolpropane, pentaerythritol, hindered ester and the like can be used.

  These lubricating base oils can be used alone or in combination of two or more, and may be used in combination of mineral oil and synthetic oil.

The kinematic viscosity of the lubricating base oil can be appropriately selected according to the use and purpose of the lubricating oil composition. For example, when using a lubricating oil composition according to the present embodiment as the drive system a lubricating oil, a kinematic viscosity at 100 ° C. of the lubricating base oil is preferably 1 to 30 mm ² / s, more preferably 2 to 20 mm ² / s More preferably, it is 3-10 mm < ² > / s. When the kinematic viscosity at 100 ° C. is in the above range, friction at sliding parts such as gear bearings and clutches of the automatic transmission can be sufficiently reduced and the low temperature characteristics are also good. On the other hand, if the kinematic viscosity at 100 ° C. exceeds 30 mm ² / s, the fuel efficiency deteriorates and the low-temperature viscosity tends to be too high. Further, if the kinematic viscosity at 100 ° C. is less than 1 mm ² / s, the lubrication performance is lowered such as an increase in wear amount in sliding parts such as gear bearings and clutches of automatic transmissions, and the evaporating property is increased, resulting in lubrication Oil consumption may increase.

Moreover,% C _A of the lubricating base oil, from the viewpoint of low temperature characteristics, it is more preferably preferably not more than 20, in particular 10 or less.

  In the lubricating oil composition according to the present embodiment, the content of the succinimide compound represented by the formula (1) is preferably 0.01 to 30% by mass from the viewpoint that the additive effect can be effectively exhibited. More preferably, it is 0.05-20 mass%, More preferably, it is 0.1-10 mass%.

  For the purpose of further improving the performance of the lubricating oil composition according to the present embodiment, an ashless dispersant and / or a friction modifier other than the succinimide compound represented by the formula (1), if necessary, a metal Various additives represented by system detergents, viscosity index improvers, extreme pressure additives, antioxidants, corrosion inhibitors, antifoaming agents, colorants and the like can be further contained. These additives can be used individually by 1 type or in combination of 2 or more types.

  Examples of the friction modifier other than the succinimide compound represented by the formula (1) include fatty acid esters, fatty acid amides, phosphorus compounds such as phosphate esters, phosphite esters, and thiophosphate esters, MoDTP, MoDTC, and the like. Examples include organomolybdenum compounds, organozinc compounds such as ZnDTP, organoboron compounds such as alkyl mercaptyl borates, solid lubricant friction modifiers such as graphite, molybdenum disulfide, antimony sulfide, boron compounds, and polytetrafluoroethylene. Of these, phosphorus compounds are preferred. The content of the friction modifier is usually 0.1 to 10% by mass based on the total amount of the lubricating oil composition.

  Examples of the antioxidant include amine-based antioxidants such as alkylated diphenylamine, phenyl-α-naphthylamine, alkylated-α-naphthylamine, 2,6-di-t-butyl-4-methylphenol, 4,4 ′. -Phenolic antioxidants such as -methylenebis (2,6-di-t-butylphenol). The content of the antioxidant is usually 0.05 to 5% by mass based on the total amount of the lubricating oil composition.

  Examples of metallic detergents include calcium sulfonate, magnesium sulfonate, barium sulfonate, calcium salicylate, magnesium salicylate, calcium phenate, barium phenate, and the like. It is usually 0.1 to 10% by mass based on the total amount of the oil composition.

  Examples of the viscosity index improver include polymethacrylates, polyisobutenes, ethylene-propylene copolymer systems, and styrene-butadiene hydrogenated copolymer systems. The content of the viscosity index improver is usually 0.5 to 35% by mass based on the total amount of the lubricating oil composition.

  The use of the lubricating oil composition according to the present embodiment is not particularly limited, and can be used in a wide range of fields such as a lubricating oil for internal combustion engines and a drive system lubricating oil. For example, since the lubricating oil composition according to the present embodiment contains a succinimide compound represented by the lubrication formula (1), it has a higher coefficient of static friction (high wet friction material) than a conventional succinimide compound. Torque capacity) and can be used as an automatic transmission oil or a continuously variable transmission oil. Further, it can be used as a lubricating oil for construction machines, agricultural machines, manual transmissions, two-wheeled gasoline engines, diesel engines, gas engines, shock absorber oils, etc., equipped with transmissions having wet clutches and wet brakes.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

Example 1 Synthesis of Succinimide Compound I
In a 2000 mL autoclave, 1.0 mol of polyisobutene (number average molecular weight 1000) and 1.0 mol of maleic anhydride are added, heated to 220 ° C. over 1.5 hours, and allowed to react for 4 hours after reaching 220 ° C. It was. After completion of the reaction, n-hexane was added to the obtained product and stirred, and the solution was filtered to remove insoluble matter. After removing n-hexane from the filtrate by atmospheric distillation, maleic anhydride was removed at 220 ° C. under reduced pressure to obtain maleated polyisobutene.
Meanwhile, 0.008 mol of phenylalanine was crushed in a mortar, placed in a 100 mL four-necked flask, and xylene was added. Next, it was made to react at 165 degreeC for 24 hours, dripping 0.004 mol of maleated polyisobutenes obtained by making it melt | dissolve in xylene. After completion of the reaction, residual amino acid was removed by filtration, and the solvent was removed by distillation under reduced pressure to obtain succinimide compound I. The obtained succinimide compound I was subjected to infrared absorption spectrum and elemental analysis, and confirmed to have a structure represented by the formula (1). The nitrogen content was 1.15 (theoretical value 1.22)%.

[Example 2; Synthesis of succinimide compound II]
In a 2000 mL autoclave, 1.0 mol of polyisobutene (number average molecular weight 2300) and 1.0 mol of maleic anhydride are added, heated to 220 ° C. over 1.5 hours, and allowed to react for 4 hours after reaching 220 ° C. It was. After completion of the reaction, n-hexane was added to the obtained product and stirred, and the solution was filtered to remove insoluble matter. After removing n-hexane from the filtrate by atmospheric distillation, maleic anhydride was removed at 220 ° C. under reduced pressure to obtain maleated polyisobutene.
Meanwhile, 0.008 mol of phenylalanine was crushed in a mortar, placed in a 100 mL four-necked flask, and xylene was added. Next, it was made to react at 165 degreeC for 24 hours, dripping 0.004 mol of maleated polyisobutenes obtained by making it melt | dissolve in xylene. After completion of the reaction, residual amino acids were removed by filtration, and the solvent was removed by distillation under reduced pressure to obtain succinimide compound II. The obtained succinimide compound II was subjected to infrared absorption spectrum and elemental analysis, and confirmed to have a structure represented by the formula (1). The nitrogen content was 0.54 (theoretical value 0.57)%.

[Comparative Example 1; Synthesis of Succinimide Compound III]
In a 2000 mL autoclave, 1.0 mol of polyisobutene (number average molecular weight 1000) and 1.0 mol of maleic anhydride are added, heated to 220 ° C. over 1.5 hours, and allowed to react for 4 hours after reaching 220 ° C. It was. After completion of the reaction, n-hexane was added to the obtained product and stirred, and the liquid was filtered to remove sludge. After removing n-hexane from the filtrate by atmospheric distillation, maleic anhydride was removed at 220 ° C. under reduced pressure to obtain maleated polyisobutene.
In a 2 L separable flask, 1.7 mol of diethylenetriamine and xylene were added. Next, it was made to react at 145-155 degreeC for 11 hours, dripping 0.17 mol of maleated polybutenes melt | dissolved in xylene. After completion of the reaction, the solvent was removed by atmospheric distillation, and residual diethylenetriamine was removed by distillation under reduced pressure to obtain succinimide compound III.

[Examples 3-8, Comparative Examples 2-4; Preparation and Evaluation Test of Lubricating Oil Composition]
In Examples 3 to 8 and Comparative Examples 2 to 4, mineral oil of SAE10 fraction (100 ° C. kinematic viscosity 4.1 mm ² / s) as a lubricant base oil, succinimide compound I, II or III, A lubricating oil composition was prepared using the additives shown in Tables 1 and 2. The composition of each lubricating oil composition is shown in Tables 1 and 2.
Next, about the lubricating oil composition of Examples 3-8 and Comparative Examples 2-4, the friction coefficient between metals was evaluated using the LFW-1 test machine. The test conditions were a surface pressure of 0.8 GPa, a sliding speed of 0.2 m / s, a test temperature of 80 ° C., a test time of 1 hour, and an average friction coefficient obtained by averaging the friction coefficients within the time. The obtained results are shown in Tables 1 and 2.

  The succinimide compound, lubricating oil additive, and lubricating oil composition of the present invention can be used in a wide range of lubricating oil fields, and are particularly suitable as automatic transmission oils and continuously variable transmission oils that require a high coefficient of static friction. .

Claims (5)

A succinimide compound represented by the following formula (1).

[In the formula (1), R represents an alkyl group or alkenyl group having a number average molecular weight of 500 or more and less than 5000. ]   The succinimide compound according to claim 1, wherein R in the formula (1) is a group derived from a polyisobutene having a number average molecular weight of 500 or more and less than 5000.   A lubricating oil additive comprising the succinimide compound according to claim 1.   A lubricating oil composition comprising a lubricating base oil and the succinimide compound according to claim 1.   The lubricating oil composition according to claim 4, further comprising a phosphorus compound.